.alpha.'-Halo .alpha.,.alpha.-disubstituted .alpha.-amino ketones are useful as intermediates in the synthesis of .alpha.,.alpha.-disubstituted azetidonones, as set forth in the co-pending applications of William W. Hargrove, Ser. No. 502,331 filed Oct. 22, 1965, now U.S. Pat. No. 3,481,920 and Ser. No. 790,852, filed Jan. 13, 1969 now U.S. Pat. No. 3,494,964.
A synthesis of .alpha.'-halo .alpha.,.alpha.-disubstituted .alpha.-amino ketones is described in Ser. No. 502,331 U.S. Pat. No. 3,481,920. According to this synthesis the desired product is obtained by treating a glacial acetic acid solution of the amino ketone with the appropriate halogen. The product is isolated in the form of the acid addition salt of Formula I. This simple, convenient, and easily performed preparation has been found to possess certain limitations, e.g., in those compounds where R.sup.3 represents a monophenyl-substituted lower alkyl group, halogenation appears to occur in the alkyl portion of said group.
It is an object of this invention to provide a method of obtaining .alpha.'-halo .alpha.,.alpha.-disbustituted .alpha.-amino ketones, which method avoids the undesirable aspects of previous methods.